In gas turbine engines, seals are provided between components to prevent either air leakage, such as between the tips of the blades and the case (outer air seals), and between the vanes and the disks (knife edge seals), or air-oil leakage, such as rotating shaft seals. The efficiency of a gas turbine engine is dependent, at least in part, upon avoidance of leakage between rotating and stationary members or between two rotating members. During operation of the gas turbine engine, seals, either rotary seals or stationary seals, tend to slide axially, i.e. parallel to the gas turbine engine components they are sealing together. These axial displacements can reduce significantly the sealing capability and the ingested particles can damage bearings, gears, and/or other components adjacent to such seal if these components ingest the particles.
Accordingly, there is a need to provide an improved seal design which restrains axial displacement.